Möbius Syndrome
- Described by Möbius as “Congenital Facial Diplegia” with bilateral abducens palsy in 1888
- Diplegia= symmetrical bilateral palsy
Cause
- Pathogenesis is unclear
- Deletion/translocation in long arm of chromosome 13 in a few families
- Timing of insult 4-6 weeks gestation when cranial nerve nuclei are rapidly developing
- Trauma, illness or toxic exposure
Clinical Features
- 6th and 7th nerve palsies
- Usually bilateral but may be asymmetric
- Esotropia most common
- “Mask-like” facies
- If incomplete palsy- upper division of facial nerve involved
Other Ocular features:
- Small palpebral fissures
- Epicanthal folds
- Hypertelorism
- Exposure or neurotrophic keratitis
- Situs inversus of retinal vessels
- Entropion
- Ptosis
- Head tilt
- Amblyopia
- Gaze palsy
Other Systemic Features
- Extremities
- Syndactyly, polydactyly, brachydactyly, agenesis of digits, clubfoot
- Swallowing and speech abnormalites from cranial V, IX and X palsies
- Craniofacial abnormalities
- Micrognathia, Microstomia, Ear abnormalities, Bifid uvula, cleft palate
- Dextrocardia
- Defective musculature
- Missing pectoral and trapezius muscles
- Absence of sternal head of pectoralis major
- Rib defects
- Tongue hypoplasia
- Mild Mental retardation
First signs:
- Difficulty sucking, drooling, incomplete closure of eyelids
- Lack of smiling response
- Other cranial nerve abnormalities:
- V, IX,X and XII can be involved
- Craniofacial abnormalities
Evaluation
- Strabismus (Esotropia)
- Amblyopia
- Corneal health
- Pediatric Genetics evaluation
- Craniofacial abnormalities in differential diagnosis
- Nager syndrome (acrofacial dysostosis)
- Neuromuscular disease in differential diagnosis
- Facioscapulohumeral (FSH) muscular dystrophy- shoulders primarily affected
- Congenital or infantile myotonic dystrophy (slow relaxation of muscles after contraction)
- Muscle wasting, cataracts, heart conduction defects, endocrine abnormalities
- Charcot-Marie-Tooth disease
- progressive loss of muscle and touch sensation in extremities
- Usually in late childhood or early adulthood
- Often first present with foot drop and claw toe
Strabismus Management
- Abnormal Extraocular muscles
- Hypoplasia, aplasia and fibrous bands
- Forced duction testing
- Vertical Rectus transposition
- Medial rectus botox (more effective if muscle not tight)
- Medial rectus recession